As is known, a plethora of portable power-operated (i.e., gas or electric) hedge trimmers are commercially available for pruning plant growth such as, for example, shrubs, hedges, stalks, small twigs and branches, and the like. Traditionally, portable hedge trimmers include a blade assembly having a pair of overlying elongated toothed blades at least one of which is reciprocally driven to establish a "shear-cutting" action therebetween. In particular, cutter teeth are formed on at least one longitudinal edge of a shearing blade which cooperate with comb teeth formed on a corresponding longitudinal edge of a combing blade for shear-cutting the plant growth introduced therebetween during a single blade stroke. In some applications, both the shearing blade and combing blade are reciprocally driven to establish a counter-reciprocating blade assembly. In other applications, the cutter teeth on the reciprocating shearing blade cooperate with the comb teeth on a stationary combing blade to likewise establish the single-stroke shear-cutting action.
A problem routinely encountered during use of a portable hedge trimmer is its inability to shear large twigs and branches due to the limited cutting path established between the relatively close spacing of adjacent cutter and comb teeth. Moreover, industry standards have been established which set forth specific limitations on the maximum size (i.e., 3/4" in diameter) of the plant growth that can be introduced into the cutting path of the reciprocating trimmer blade(s). Despite the existence of this maximum size limitation, many conventional hedge trimmers are designed to only accept introduction of plant growth up to 3/8" in diameter due, in large part, to the additional power requirements needed for shearing larger twigs and branches. Thus, it is commonly necessary for any plant growth of a size exceeding such size limitations to be pruned using a different cutting tool such as, for example, a hand saw or a power-operated reciprocating saw or chain saw.
In an effort to overcome the above-noted shortcomings and limitations, it has been proposed to install a reciprocating saw as an adjunct to the blade assembly for enabling the hedge trimmer to establish a "saw-cutting" action in addition to the "shear-cutting" action. In most instances, an auxiliary saw blade segment is either mounted to, or formed as an integral extension of, at least one of the reciprocally movable trimmer blades. Various examples of such a combination hedge trimmer and reciprocating saw are shown and disclosed in U.S. Pat. No. 3,143,798 to Lundquist, U.S. Pat. No. 3,217,408 to Jepson, and U.S. Pat. No. 4,280,276 to Comer et al. While these combination power tools provide a greater capacity for cutting shrubbery, each requires special manipulation to be used effectively. More specifically, the operator must use the hedge trimmer section of the reciprocating blade assembly for shearing the smaller plant growth while the reciprocating saw section of the reciprocating blade assembly is used for sawing the larger twigs and branches. Thus, the operator is required to cognitively classify the plant growth by size prior to engaging the corresponding cutting section of the blade assembly therewith. This requirement places an encumbrance on the operator limiting concurrent use of the hedge trimmer section and the reciprocating saw section of the combination power tool since the cutting rate for each section is different. As is also apparent, such combination hedge trimmers are rather bulky and overly cumbersome, requiring greater dexterity on the part of the operator as compared to use of traditional hedge trimmers, and are inherently more expensive due to inclusion of the auxiliary saw blade components.